SU1006495A1 - Method for smelting steel in acid open-hearth furnace - Google Patents

Abstract

1. METHOD OF MELTING STEEL IN 1 ACID MARTENOVO FURNACE flint; 1, the incorporation process including; smelting of the intermediate product in the 6th main; steel-smelting unit, pouring it into an acidic open-hearth furnace and finishing it to the required chemical composition, which, in order to improve the quality of the steel produced and reduce the consumption of manganese-containing ferroalloys and pig iron, boil catalysts in the period of boiling into the metal silicon in the amount of 0.005-0.03% by weight of the charge. 2. The method according to p. 1, I distinguish. As well as with the fact that as kataI, lysators, elements are used that have a high affinity for oxygen and carbon.

Description

about

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The invention relates to ferrous metallurgy and can be used in the metallurgical and engineering industries in the smelting of steel in acidic open-hearth furnaces.

There is a known method of steel smelting in acid open-hearth furnaces, according to which iron and scrap with a low content of sulfur and phosphorus are used to produce steel. 1

The disadvantages of the method are the high cost. And the scarcity of the metal part of the construction materials.

The closest to the invention to the technical essence and the achieved result is a method of steel smelting in an acid open-hearth furnace by a silicon recovery process, which includes the smelting of the intermediate product of the main steelmaking unit, its overflow into the acid open-hearth furnace and fine-tuning to the desired chemical composition 2J.

The disadvantages of this method are the high consumption of pig iron and manganese-containing ferroalloys and the unstable quality of the produced steel due to contamination with its products by scouring the hearth.

The aim of the invention is to improve the quality of the steel produced and to reduce the consumption of manganese-containing ferroalloys and cast iron.

The goal is achieved by the fact that according to the method of steel smelting in an acidic open-hearth furnace by a silicon reduction process, including the smelting of the intermediate product in the main steel-smelting unit, its overflow into an acidic open-hearth furnace and fine-tuning to the required chemical composition, silicon recovery catalysts in the amount of 0,0050, 03% of the weight of the cages.

In this case, it is advisable to use elements that have a high affinity for oxygen and carbon as catalysts.

The introduction of a catalyst in an amount of less than 0.005% does not lead to a noticeable increase in the rate of silicon reduction and a change in the amount of non-metallic inclusions.

An increase in catalyst consumption above 0.03% leads to a partial deoxidation of the steelmaking bath, a sharp decrease in the oxidation rate of carbon, and consequently, an increase in the boiling period.

It is known that silicon reduction occurs mainly by reaction.

(SiOj) +, + 2

(SiO + 2 MnJj :: si -t- 2 (MnO),

The introduction of catalysts allows to increase the rate of the reaction of silicon reduction by carbon and thereby reduce the carbon stock and consumption of ferromanganese, as well as to lead smelting at the optimal rate of carbon oxidation, preventing a strong erosion of the hearth during intensive boiling of the bath.

The effect of catalysts on the process of reducing silicon is described by the following equations:

(Sio x -lsri f

, (CW) + .2 ui Xj + 2 {CO}

(SiOj) + 2 C-isil. + 2 co

The method is carried out as follows.

In the main open-hearth furnace, a 5-LIQUID intermediate is melted, then it is released into a ladle and poured into an acidic furnace. Before the overflow, circulating acidic slag in the amount of 4.5-6.0% by weight of the entire metal charge is poured onto the hearth of the acid furnace. Cast iron and ferrous metal waste are poured onto the slag.

After the bath begins to boil, catalyst additives are produced in the amount of 0.05-0.3 kg / ton of liquid steel. The manganese content is not regulated during the refinement period. After obtaining the carbon content and the cream in the metal within the specified limits, it is deoxidized and alloyed. The metal is produced with overheating of the SO-HZO C above the melting temperature of the steel grade.

Example. The proposed method produced molten steel of the 38KhNZMFA brand with the chemical composition according to GOST 4543-7%: C 0.33-0.40} Mp 0, Si 0.17-0.37 j Cr 1.20-1.50, Ni 3.003, 50 ; Mo 0.35-0.45; V 0.10-0.18; s

not more than 0.025 and P not more than 0.025.

In the main open-hearth furnace the intermediate product of the following chemical composition is melted,%: C 0.81, Mp 0.48 S 0.015, - P .0.011, Cg 0.26, Ni 2.86 and Mo 0.37.

Nickel and molybdenum are loaded into the basement of an acidic furnace at the rate of obtaining these elements within the specified chemical composition. The melting process in an acidic open-hearth furnace is given in table. one.

f a b l and c ai 1

 In tab. Table 2 shows the results of a study of the effect of high technology when steel smelting on the contamination of its non-metallic inclusions,

table 2

Claims (2)

1. METHOD FOR Smelting STEEL IN I SURFACE OF THE MARTIN FURNACE - flint! formation process> including smelting of the intermediate product in the main (steelmaking unit, pouring it into an acid open-hearth furnace and * adjusting to the required chemical composition, characterized in that, in order to improve the quality of the smelted steel and reduce the consumption of manganese-containing ferroalloys and cast iron, they are introduced into the metal during boiling silicon reduction catalysts in an amount of 0.005-0.03% by weight of the charge. 2. The method according to π. 1, due to the fact that, as kata ₍₍ lysator, elements with a high affinity for oxygen and carbon are used).